In magnetic storage systems, a magnetic disc rotates at high speeds. A read/write transducing head “flies” over the surface of the disc carried on a slider and is used for reading and writing information. The slider has certain hydrodynamic properties that provide lift while the drive rotates. This lift is counteracted by a spring loaded flexure armature which supports the slider. The slider reaches an equilibrium fly height based principally upon the speed of rotation of the disc, the hydrodynamic properties of the slider and the spring tension of the flexure armature. Improved reading and writing characteristics are achieved as the slider flies closer to the disc surface.
Various techniques have been used to measure the fly height of a slider. One technique to measure fly height is by measuring electrical capacitance between the slider and the disc. Another common technique to measure fly height uses optical methods. Yet another technique uses the amplitude of magnetic read back signals to determine fly height. A well known equation for determining fly height using amplitude of readback signals is known as the “Wallace equation”. Current methods using the Wallace equation use a prerecorded portion of data to measure the readback signals. Accordingly, fly height can only be measured on the portion having the prerecorded data. Additionally, current methods have relatively low precision. Embodiments of the present invention provide solutions to these and other problems, and offer other advantages over the prior art.